ISO 18902:2001

INTERNATIONAL ISO
STANDARD 18902
First edition
2001-09-01
Imaging materials — Processed
photographic films, plates and papers —
Filing enclosures and storage containers
Matériaux pour image — Films, plaques et papiers après traitement —
Contenants pour classement destinés à l'archivage
Reference number
ISO 18902:2001(E)
©
ISO 2001

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ISO 18902:2001(E)
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ISO 18902:2001(E)
Contents Page
Foreword.iv
Introduction.v
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Materials .2
4.1 General.2
4.2 Paper and board.3
4.3 Plastic .4
4.4 Metal.4
4.5 Adhesives.4
4.6 Printing inks .4
5 Enclosures.5
5.1 General.5
5.2 Enclosure types .5
5.3 Dimensions.7
5.4 Seams .7
6 Material and construction selection .7
Annex A (informative) Numbering system for related International Standards.9
Annex B (informative) Distinction between storage (record) copies and work (reference) copies.11
Bibliography.12
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ISO 18902:2001(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 18902 was prepared by Technical Committee ISO/TC 42, Photography.
This first edition cancels and replaces ISO 10214:1991, of which it constitutes a technical revision.
This International Standard is one of a series of International Standards dealing with the physical properties and
stability of imaging materials. To facilitate identification of these International Standards, they are assigned a
number within the block from 18900 – 18999 (see annex A).
Annexes A and B of this International Standard are for information only.
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ISO 18902:2001(E)
Introduction
Photographic materials, including black-and-white and colour reflection prints, films, plates, and diazo prints and
transparencies, have become increasingly important as documentary and pictorial reference materials in archives,
libraries, government, commerce and academia. This has focused attention on the importance of preservation of
such materials to ensure their longest possible life.
The stability and useful life of photographic materials depends on their physical and chemical properties, as well as
on the conditions under which they are stored and used. The important elements affecting the useful life of
photographic materials are as follows:
� humidity and temperature of the storage environment;
� hazards of fire, water, and light exposure;
� fungal growth;
� contact with certain chemicals in solid, liquid or gaseous form;
� physical damage;
� proper processing;
� enclosures and containers in contact with the photographic material.
International Standards have been written specifying the stability requirements for different types of photographic
film: ISO 18901, ISO 18905, ISO 18912 and ISO 18919 (see [10, 11, 13, 15] in the bibliography).
Recommended storage conditions are given in the following standards for different photographic materials:
ISO 18911, ISO 18918 and ISO 18920.
This International Standard is an auxiliary document and deals specifically with the enclosure materials used in
storage. It pertains to the materials used in filing enclosures, containers and albums, as well as to construction
details used in folders, sleeves, jackets, envelopes, pocket pages, and slide mounts. In addition, ISO 14523
describes the test method used to evaluate filing enclosure materials for photo-reactivity, referred to in this
International Standard.
The term "archival" is no longer used in International Standards for defining optimum storage conditions and
enclosures, because the meaning of "archival" has become too ambiguous. In common usage, "archival" has been
used to mean that documents can be preserved "forever". The new terms, when applied to the storage standards
mentioned above are “extended-term” and “medium-term”. Likewise, enclosure materials should not be referred to
as "archival", but rather as meeting the specifications of this International Standard and ISO 14523.
When filing processed films, plates or papers, it is customary and good practice to enclose these photographic
materials in envelopes, sleeves, folders, or other forms of enclosure in order to exclude dirt, protect them against
mechanical damage, and facilitate identification and handling.
Storage conditions for photographic records can be designed for extended-term preservation or for moderate
periods of time. The storage protection required in each case will differ in degree according to the cost of providing
storage facilities, the desired record life, and the frequency of record use. Storage conditions shall be chosen within
specified limits in order to obtain a satisfactory compromise between the degree of protection required and the
practical consideration of immediate availability.
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ISO 18902:2001(E)
Specifying the chemical and physical characteristics of the photographic and enclosure materials does not, by
itself, ensure satisfactory storage behaviour. It is essential also to provide proper storage temperature and
humidity, as well as protection from the hazards of fire, water, and fungal growth; from contact with certain
chemicals in solid, liquid or gaseous form (e.g., atmospheric pollutants); and from physical damage.
Furthermore, different types of photographic materials may respond uniquely to varying storage conditions. Since
solid particles abrade prints and negatives when being slid in and out of filing enclosures or when stacked items are
sorted, and because such particles can sometimes be chemically destructive to images and base materials, clean,
dust-free storage areas are essential. Atmospheric conditions, natural and man-made, shall be controlled since
paper and plastic enclosures are permeable and they do not protect the photographic image from environmental
effects. Such effects include non-recommended relative humidities, or atmospheric pollutants such as hydrogen
sulfide, sulfur dioxide, nitrogen oxides, and peroxides.
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INTERNATIONAL STANDARD ISO 18902:2001(E)
Imaging materials — Processed photographic films, plates and
papers — Filing enclosures and storage containers
1 Scope
This International Standard specifies the principal physical and chemical requirements for filing enclosures, albums,
and containers particularly designed for storing processed photographic films, plates and papers. The photographic
image may be silver-gelatin type, colour (dye-gelatin), diazo or vesicular.
This International Standard applies to storage copies and does not include work copies as defined in informative
annex B. The requirements are limited to the characteristics that may affect the enclosed item chemically or
physically when it is stored under recommended conditions. (For methods of proper storage, see ISO 18911,
ISO 18918 and ISO 18920, see [12, 14, 16] in the bibliography.)
2 Normative references
The following normative documents contain provisions, which, through reference in this text, constitute provisions
of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 699:1982, Pulps — Determination of alkali resistance
ISO 6588:1981, Paper, board and pulps — Determination of pH of aqueous extracts
ISO 10716:1994, Paper and board — Determination of alkali reserve
ISO 14523:1999, Photography — Processed photographic materials — Photographic activity test for enclosure
materials
1)
ASTM D 1030-95, Standard Test Method for Fiber Analysis of Paper and Paperboard, Appendix X5
2)
TAPPI T236om-99, Kappa number of pulp
2)
TAPPI T406om-94, Reducible sulfur in paper and paperboard
2)
TAPPI T408om-97, Rosin in paper and paperboard
1) Available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428, USA.
2) Available from the Technical Association of Pulp and Paper Industry, Box 105113, Technology Park, Atlanta, GA 30348,
USA.
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ISO 18902:2001(E)
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
3.1
anti-blocking agent
component of a material that provides microscopic bumps on the surface in order to minimize contact area and
reduce the coefficient of friction
NOTE Examples are talc and silicates.
3.2
ferrotyping
glazing
changing of surface characteristics resulting from contact of two surfaces
3.3
Newton's rings
faint coloured rings or fringe patterns formed by the interference between a direct and a reflected beam of light
generated by two transparent surfaces in close contact
3.4
slip agent
component of a material added to a surface so as to reduce the coefficient of friction
NOTE Slip agents are usually amide-type materials.
4 Materials
4.1 General
The enclosure material should be free of acids and peroxides that may be released slowly with time and cause
degradation to the image or various components of the photograph. For example, ageing blemishes in processed
silver gelatin microfilm may be caused by chemicals such as peroxides evolved from the paper (see [1, 2] in the
bibliography). Likewise, the presence of acid in paper can cause paper degradation.
The enclosure itself shall be chemically stable. Otherwise, the decomposition products might be harmful to the
photographic material, and dirt or dust might be produced that could scratch, or become embedded in the image
surface. Cellulose nitrate, polyvinyl chloride, and glassine sheeting are examples of enclosure materials that are
either chemically or physically unstable and shall not be used (see [3, 4] in the bibliography).
The surface of the enclosure material is also important. The enclosure shall not abrade the photograph. While a
slightly textured or matte surface is recommended for the filing enclosure to minimize ferrotyping (see below), a
rough surface can produce abrasion problems. There may be other harmful physical characteristics of the
enclosure material that may develop under adverse environmental conditions e.g., elevated relative humidity.
These include wrinkling and distortions common to glassine paper or ferrotyping of the image surface, i.e., local or
overall glazing that can result from contact under pressure with smooth, glossy, plastic enclosure materials. Finally,
enclosures shall be of sound and sturdy construction so that the enclosure functions properly during use, without
seams or fabrication components failing or otherwise damaging the photographs during storage.
Paper, cardboard, and plastic enclosure materials, slide mounts, inks and adhesives shall meet the requirements of
the photographic activity test as described in ISO 14523. This incubation test determines whether these materials
have a chemical interaction with silver, colour or diazo images or cause stain in a gelatin binder (see [5] in the
bibliography). The photographic activity test is also applicable for testing chemical interactions caused by album
storage materials
If a particular brand of commercially made paper, cardboard, or plastic enclosure material, ink, and adhesive is
found to be safe for long-term storage purposes (i.e., passes ISO 14523 and does not fail with use or cause
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ISO 18902:2001(E)
physical damage), there is no assurance that subsequent batches will contain ingredients of the same purity,
chemical inertness, or sound and sturdy construction. Subsequent batches shall require evaluation and testing
according to this International Standard and ISO 14523.
4.2 Paper and board
4.2.1 Basic requirements
Paper and cardboard shall meet the requirements of the photographic activity test described in ISO 14523.
4.2.2 Paper cartons and boxes
Paperboard and corrugated cartons, boxes, or containers that are not in direct contact with the photographic
material shall have a pH between 7,0 and 9,5, as determined by the method specified in ISO 6588.
An alkali reserve shall be the molar equivalent to at least 2 % calcium carbonate (CaCO ), as determined by the
3
alkali reserve test described in ISO 10716. This alkali reserve shall be accomplished by the incorporation of an
alkaline earth carbonate or equivalent. (Compounds such as magnesium carbonate (MgCO ) and zinc oxide (ZnO),
3
in molar equivalencies, correspond to approximately 1,6 % reserve. This has the same effect as 2 % molar
equivalencies of CaCO ). The alkali reserve shall be evenly distributed throughout the paper or paperboard.
3
4.2.3 Paper enclosures in direct contact with black-and-white and colour photographic images
Paper that is in direct contact with photographic material shall be made from high alpha-cellulose, bleached sulfite,
or bleached kraft pulp with an alpha-cellulose content greater than 87 %, as determined by the method given in
ISO 699. The paper shall be free from highly lignified fibres such as groundwood (ASTM D 1030 Appendix X5,
TAPPI T 236om), alum rosin sizing (TAPPI T 408om), particles of metal, and shall contain less than 0,000 8 %
reducible sulfur (TAPPI T406om).
The pH shall be between 7,0 and 9,5 as determined by the method given in ISO 6588. The alkali reserve shall be
the molar equivalent to at least 2 % CaCO , as determined by the alkali reserve test described in ISO 10716. This
3
alkali reserve shall be accomplished by the incorporation of an alkaline earth carbonate or the equivalent, as
described below. The alkali reserve shall be evenly distributed throughout the paper or paperboard.
A minimum of sizing chemicals shall be used, the amount being dictated by the requirements of the end use
(enclosures, overwraps, interleaving, etc.). If sizing is used, neutral or alkaline sizing chemicals (internal and/or
surface) shall be employed. Dyes or pigments used to colour the paper shall show no bleeding or transfer when
soaked in distilled water for 48 h while held in direct contact with white bond paper.
The surface of the paper shall be free of knots, shives and other abrasive particles. Surface fibres that might offset
onto photographic layers should not be present. The paper shall not contain waxes, plasticizers, or other
ingredients that may transfer to the photographic material during storage.
The paper shall meet the physical tests required for the particular application. These include folding endurance
(see ISO 5626), tear resistance (see ISO 1974) and tensile strength (see ISO 527-3) (see [8, 7, 6] respectively in
the bibliography).
Under prolonged direct contact in adverse environmental conditions of high relative humidity or immersion in water,
paper with a pH greater than 8,0 may cause increased yellow stain formation and cyan dye fading in chromogenic
colour photographs or diazo dye formation in processed diazo photographs. It should also be noted that the pH of
paper will decrease with age, especially in highly polluted environments or when used to enclose acidic
photographic materials, leading to embrittlement and discolouration. For this reason, an alkali reserve is generally
recommended for the permanence of the enclosure paper. CaCO and MgCO at a molar equivalent to 2 %
3 3
CaCO will result in a pH greater than 8,0 (approximately pH 8,6 and 9,6, respectively). Enclosures that have
3
become highly acidic should be replaced to avoid deleterious effects on dye stability, e.g., cyan dyes may convert
to colourless leuco dye forms at a pH of 5,5 to 6,0.
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ISO 18902:2001(E)
4.3 Plastic
Plastics shall meet the requirements of the photographic activity test described in ISO 14523.
A suitable plastic enclosure material is polyester [poly(ethylene terephthalate)]. In addition, polystyrene,
polyethylene, polypropylene, and spun-bonded polyolefins generally have been found suitable as they are usually
inert, unplasticized, and have good chemical stability. Other plastics may be satisfactory, but there has been no
extended experience with such materials. Chlorinated or nitrated sheeting, such as polyvinyl chloride and cellulose
nitrate, shall not be used.
Highly plasticized sheetings or coatings shall not be employed, as this might result in either sticking or ferrotyping
of the image surface. Plastics of unknown quality containing residual solvents or plasticizers are suspect, because
these chemicals may escape and have a harmful effect on the photographic image.
Plastics used for containers shall contain anti-oxidants and non-halogenated fire retardants, such as antimony
oxide.
Most plastic sheeting used for enclosures contains slip agents and anti-blocking agents, in order to lower the
coefficient of friction on the surface to prevent blocking of the sheets. In some plastics, these components may
migrate from the body of the plastic sheeting to the surface, where they redeposit as an oily residue that may
transfer to the photograph stored inside the enclosure. In addition, this oily film may attract dust and other foreign
matter that could cause abrasion or otherwise deteriorate the photograph. Currently there is no standard test
procedure to evaluate the suitability of slip agents and anti-block agents in plastic enclosures for long-term storage
of photographs.
The plastic shall meet the physical tests required for the particular application. These include folding endurance
(see ISO 5626), tear resistance (see ISO 6383-2) and tensile strength (see ISO 527-3), see [8, 9, 6] respectively in
the bibliography).
4.4 Metal
Metals used for cores, reels, and containers shall be noncorrodible, such as anodized aluminum or stainless steel.
The use of steel is permissible, provided the surface is well-protected by powder coating, tinning, plating, or some
other corrosion-resistant finish. Lacquer or enamel that might give off reactive fumes, peroxides or exudations
during storage shall not be used. Metal finishes shall meet the requirements of the photographic activity test
described in ISO 14523.
4.5 Adhesives
Adhesives used to cement (paste) enclosure seams and laminate paperboard plies shall meet the requirements of
the photographic activity test described in ISO 14523. Some photographic images can be damaged by adhesives
that contain impurities such as sulfur, iron, copper, or other ingredients that might attack image silver, gelatin, or
film and paper supports. Various adhesives are hygroscopic, thus increasing the possibility of local chemical
activity. Many adhesives discolour with age, staining any material with which they are in contact, or fail over time
causing enclosure seams to open up. Pressure-sensitive adhesives generally have poor long-term stability
characteristics and should be avoided.
Rubber-based products, such as rubber cement, shall be avoided. Not only might they contain harmful solvents or
plasticizers, they might also be compounded with photographically damaging sulfur, usually a vulcanizer,
accelerator or stabilizer. Even some "low-desensitizing" or "sulfur-free" rubbers contain sulfur.
4.6 Printing inks
Printing inks have been known to cause microscopic spots in fine-grain silver microfilm (see [1] in the bibliography);
consequently, there shall not be any printed matter on the inside of the filing enclosure. The ink used for imprinting
filing enclosures shall not bleed, spread or transfer when soaked in distilled water for 48 h while held in direct
contact with white bond paper. In addition, the ink shall not be a source of products that attack the photograph or
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ISO 18902:2001(E)
the enclosure itself. To ensure that the ink is inactive, it shall pass the photographic activity test described in
ISO 14523.
5Enclosures
5.1 General
This clause describes several types of enclosures for processed photographic materials and possible materials of
construction. The advantages and disadvantages of each are also discussed. The choice depends on the degree
of protection required, the frequency of use, and the application of the photographic material.
5.2 Enclosure types
Enclosures in close or direct contact with film, plate or paper include reels, cans, bags, folders, sleeves (sheaths),
pocket pages, jackets, envelopes, window mounts or mats, slide mounts, cartons, albums and aperture cards. All
materials used in fabricating enclosures shall comply with the appropriate requirements of clause 4.
5.2.1 Album
An album is a binder or book structure having front and back covers (usually opaque and rigid) in which pages are
bound along one edge either by glueing, sewing, or by metal posts or rings.
Photographs stored in albums may be attached to paper pages, that may have protective plastic cover sheets, or
inserted into pocket pages or envelopes. In order to protect the three open sides of an album from light and dust, a
slipcase may be used (a narrow box with an open end into which the album is inserted) or the album may be
placed into a carton or box.
5.2.2 Aperture card
This is a processible card of standard dimensions with one or more openings into which a microfilm frame or
frames can be mounted or inserted.
5.2.3 Can
A can is a metal or plastic container for a roll of recording material such as photographic film or magnetic tape.
5.2.4 Carton or box
A carton or box is an outer container that can hold one or more individual units. It may be a fabrication of paper,
card stock, or plastic.
5.2.5 Cartridge
A cartridge is a housing for a roll of recording material, such as photographic film or magnetic tape, attached to a
single hub or reel.
5.2.6 Cassette
A cassette is a housing for a roll of recording material, such as photographic film or magnetic tape, whose ends are
attached to two hubs or reels.
5.2.7 Envelope (bag)
An envelope is a paper or plastic enclosure that is cemented, mechanically joined, heat-sealed, or ultrasonically
welded on two edges with a bottom fold and one end open. A cemented bottom seam shall not be used, because
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ISO 18902:2001(E)
the contents tend to slide to the bottom of the envelope. The adhesive used on the edges shall not extend beyond
the overlap or into the interior of the envelope. The width of any sealed flaps shall be as narrow as practical to
reduce pressure differential effects upon the photographic material.
The envelope may or may not have a protective flap at the open end to provide additional protection against
contamination by dust. If a flap is used, it shall not have adhesive or be sealed with tape or rubber bands. If there is
no flap, some degree of dust protection is obtained when the open end is not used as the top. Envelopes made
from plastic sheeting may also have a sealable mechanism along the open end, such as interlocking grooves, that
offer protection against contamination by dust or infiltration of water.
5.2.8 Folder
A folder consists of a single sheet that is folded and does not have cemented seams. Folders may be made from
either paper or plastic.
NOTE Enclosures for microfiche frequently have the front side lower than the full height of the back side to permit
easy reading of the eye-legible header normally found on microfiche and jackets. This modification does not offer
as much protection from dirt as a full panel, but it makes access to the microfiche very convenient.
5.2.9 Jacket
A jacket consists of two transparent plastic sheets separated by divider strips with single or multiple film channels
made to hold single or multiple microfilm images. Channels may also be formed by heat-sealing, ultrasonic welding,
or by a bead of polyester adhesive. The channels shall be designed to permit insertion of the processed
ph
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